Hydrofoil craft



United States Patent Harold E. Follett [72] inventor 100 Reamer Ave., Wilmington, Del. 19804 [21] Appl. No. 725,403 [22] Filed April 30, 1968 [45] Patented Dec. 15, 1970 [54] HYDROFGIL CRAFT 13 Claims, 8 Drawing Figs.

[52} U.S. Cl. 114/665 [5]] int. Cl. B63b 1/22 [50] Field of Search 1 14/665 [56] References Cited UNITED STATES PATENTS 2,972,974 2/1961 Follett 114/665 3,094,962 6/1963 Goar 1 14/665 Primary Examiner--Andrew H. Farrell AttorneyRobert W. Black ABSTRACT: A combination support and hydroskifoil is provided which is easy to construct since the support and hydroskifoil are of three sections which can be stamped or molded in one piece. The support and hydroskifoil is mounted as one piece in an assembly in the under surface of a watercraft where the angle of incidence can be adjusted. The three sections of the hydroskifoil are the first hydrofoil section which extends from and below both sides of the craft and is operatively connected thereto and provides lift during acceleration, the second hydrofoil section which is connected to each end of the first section and provides additional lift when the first section is raised out of the water, and the third section is a hydroski which is disposed downwardly and rearwardly of the second section and preferably has a less transverse dimension than the second section and is in contact with the water after the first and second sections have provided lift to attain high speeds.

INVENTOR HAROLD E. FOLLETT ATTORNEY iPATENTED um m gum 3M 3,.

INVENTOR HAROLD E. FOLLETT' ATTORNEY IYDROFO I. CRAFT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to hydroskifoils for lifting and supporting watercraft through or on the surface of water or on other surfaces and adjustment mechanisms therefor.

2. Prior Art' I I I-Iydrofoils and hydroskifoils such as disclosed in U.S. Pat. No. 2,972,974 have been effective to provide fast and smooth riding watercraft. This effectiveness is marred to some extent by the complexity and number of parts required for the supports and the hydrofoils themselves. Construction is thus difficult due to the necessity of molding or stamping various parts and then assembling the parts into the hydrofoil, the support and suspension structures and structures for connecting the hydrofoil and support structure to the craft. Such a construction technique is difficult and can be expensive.

' SUMMARY OF THE INVENTION According to the present invention there is provided a device for lifting and supporting watercraft under or above a water surface, said device comprising" .a support and hydroskifoil of three sections inclined downwardly and rearwardly with respect to said craft, said first section extending from and below both sides of said craft and being a suspension support and hydrofoil connected with said craft to maintain said craft under water or to provide lifi during acceleration to raise said craft out of the water, two secondsections each of which is a hydrofoil connected to each end of said first section which provides additional lift with'said first section and lift when said first section is raised out of the water, two third sections each of which is a hydroski disposed rearwardly and downwardly of each second section, said third section being in contact with the water after the first and second sections have provided lift to obtain high speeds.

There is also provided an'article comprising a watercraft, the hydroskifoil of the present invention, said craft having a recess on its under surface for mounting the hydroskifoil therein; at least one downwardly extending member from said craft; means on""said member for receiving one edge of the DETAILED DESCRIPTION OF THE I VENTION Brief Description of the Drawings FIG. 1 is a plan view of a watercraft equipped with a hydroskifoil of this invention;

FIG. 2 is a side view of the craft shown mounting assembly;

FIG. 3 is a side detailed view of the mounting assembly;

FIG. 4 is a plan view of the hydroskifoil of this invention;

FIG. 5 is a front view of the hydroskifoil of this invention;

FIG. 6 is a plan view of various shapes of the second and third sections of the hydroskifoil of this invention;

FIG. 7 is a partial plan view of the hydroskifoil showing the various tabs used to secure the hydroskifoil to the craft; and

FIG. 8 is a cross-sectional view illustrating various airfoil shapes of the hydroskifoil component sections.

inFIG 1 showing the Detailed Description With reference to the drawings there is shown a boat 10 which, for purposes of illustration, is driven by'propeller 11 mounted at the stern. While the boat can be of any configuration of a watercraft in length and width, the boat shown merely illustrates the combination of a watercraft with the hydroskifoil and mounting assembly of the present invention without attempting to show drive. and steering control mechanisms concerned with the stern portion of the craft. Boat 10 has a sail 12 upon which rubber band mounting 13 is attached. Tail sectionl4 has a propeller shaft hole through which the shalt connects propeller II and rubber band 15.

Craft 10 shown in FIGS. 1 and 2 with airplane propeller and rubber band, engine, jet or motor drive can have the shape of a submarine, boat, airplane, dolphin, shark, fish or any other similar design and can be built as a large craft or a craft of toy size to be used either underwater or Over water, ice, snow and on land.

The stem hydroskifoil 16 can be equipped with a rudder 17 which acts also as a fin for travel over ice or snow. The stem hydroskifoil is pivotably mounted on the under surface of the stern tail l8 and the rudder is mounted under the hydroski portion 19 of the hydroskifoil. Both the hydrofoil portion 20 and hydroski portion 19 of the hydroskifoil are of airfoil shape in cross section such as any of those shown in FIG. 8.

The mounting assembly 21 for the forward hydroskifoil 22 which pivotably adjusts the angle of incidence has a recess 23 in the under surface of craft 10 for operatively mounting the hydroskifoil therein. As described in U.S. Pat. No. 2,972,974, a hydroskifoil is a device whose function is as a support, a hydrofoil and a hydroski. At the rearward edge of the recess 23 is at least one downwardly extending member 24; in the embodiment shown in the figures two downwardly extending members are positioned on each side of the craft which are curved slightly in the forward direction so',-as the back edge 25 of hydroskifoil 22 is lowered, the hydroskifoil can still be positioned in the various notches 26. Of course, the downwardly extending member can be mounted at the front edge of the recess 23, but further into the craft. In this case, the hydroskifoilis pivotably adjusted about the back edge of the hydroskifoil and, as the front edge 27 is raised, the notches receive the front edge to position the hydroskifoil in various riding positions.

For the mounting assembly shown, thenormal riding position for the hydroskifoil 22 in smooth water is accomplished by placing back edge 25 in the notch 28 closest to the craft 10. In this position the craft has a low incidence angle. For rough water, the back edge is lowered into one of the lowermost notches. The craft can perform underwater turns and loops by placing the back edge 25 in lowermost notch 29. The groove 30 at the front edge of recess 23 is cut so that it will receive the front edge 27 at its extreme positions of incidence angles, normally 3 to 20, but usually 8 to 14. The horizontal notch 31 in the back edge of downwardly extending member 24 receives mounting rubber bands 38 that hold the hydroskifoil in position and to the craft.

The hydroskifoil 22 comprises three sections, all of which are disposed downwardly and forwardly with respect to craft It) and are of airfoil cross section such as any of those shown in FIG. 8. The first section 32extends from both sides of the craft 10 and is curved forward and down so that it serves as both a suspension support and hydrofoil. The hydroskifoil can have various types of tabs 33, 33' and 33" as shown in FIGS. 4 and 7, positioned on each side of the craft body for securing the hydroskifoil to the craft. One end of one or two rubber bands 38 fits over tabs 33 and the other end is secured to the craft 10 by placing it in notch 31 in the back edge of downwardly extending member 24. Since the first section is operatively connected to the craft through the rubber bands and mounting assembly 21, the hydroskifoil can be adjusted to various positions to either maintain the craft under water or to provide lift during acceleration to raise the craft out of the water. The large surface area of the first section raises the craft out of the water very rapidly.

Second sections 34 are hydrofoils which are an extension of first section 32 and provide additional lift with the first section and lift when the first section is raised out of the water. At this The preferred form of the second sections is shown in FIG. 4; however, they can be modified as shown in F IG. 6. In these modifications, second sections 34 are of the same transverse dimension as third sections 35 and for the second section shown in FIG. 6b, the point of the hydrofoil can be curved up slightly as shown in FIG. 8d. As with stem hydrofoil 16, the second sections can be provided with detachable wheels to enable the craft to operate over land.

The hydrofoil third sections 35 are disposed downwardly and rearwardly of second sections 34 and are in contact with the water after the first and second sections have provided lift to attain high speeds. As shown in FIG. 4, the third sections are of less transverse dimension than the second sections. If desired, the third sections can be provided with downwardly extending fins 36 from the inside edge 37 to give stability to the craft at high speeds and to provide a surface for traveling over ice and snow.

The thicker pontoonlike airfoil cross section shown in FIG. 8e can provide partial or total buoyancy to any or all of the three sections while the craft is still in the water or under acceleration. It can also provide additional lift in rough water.

The combination support and hydroskifoil of the present invention enables it to be stamped from a single piece of metal or formed in plastic from one mold. Although this is preferred, the three sections can be secured by other, means such as welding, riveting or glueing.

l claim:

I. An article comprising a watercraft, a device comprising a support and hydroskifoil-of three sections including sections inclined downwardly and rearwardly with respect to said craft, said first section extending from and below both sides of said craft and being a suspension support and hydrofoil connected with said craft to maintain said craft under water or to provide lift during acceleration to raise said craft out of the water, two second sections each of which is a hydrofoil connected to each end of said first section which provides additional lift with said first section and lift when said first section is raised out of the water, two third sections each of which is a hydroski disposed rearwardly and downwardly of each second section, said third sections being in contact with the water after the first and second sections have provided lift to attain high speeds, said craft having a recess on its under surface for mounting the support and hydroskifoil device therein; at least one downwardly extending member from said craft; means on said member for receiving one edge of the support and hydroskifoil device and holding it in position and means to position the edge at the desired position and pivotably adjust the angle of incidence.

2. The article of claim 1 wherein the third section is of less transverse dimension than said second section.

3. The article of claim 1 wherein the second section and third section have the same transverse dimension.

4. The article of claim 1 wherein said three sections are of airfoil shape in cross section.

5. The article of claim 4 wherein at least one of said three sections is of pontoon airfoil shape in cross section.

6. The article of claim 1 wherein at least one of said three sections is a pontoon in function to provide partial or total buoyancy.

7. The article of claim 1 wherein the forward portion of said second section is curved upward.

8. The article of claim 1 wherein each third section has a downwardly extending fin from the inside edge.

9. The article of claim 1 wherein the downwardly extending member extends from the under surface of said craft at the rearward end of said recess and the edge receiving means in said member receive the back edge of said hydroskifoil such that the angle of incidence is pivotably adjusted at the forward edge of said hydroskifoil.

10. The article of claim 9 wherein the means for receiving one edge of the hydroskifoil are notches in the downwardly extending member.

11. The article of claim 1 wherein the craft comprises a hull;

a structure mounted on the forward, top portion of said hull; a tail fin mounted on the rearward, top portion of said hull; propulsion means; a tail fin mounted on the rearward, bottom portion of said hull; and a stern hydroskifoil pivotably mounted on the under surface of said bottom tail fin adapted to guide said craft. 7

12. The article of claim 11 wherein an airplane propeller is mounted on said top tail fin and operatively connected to said propulsion means.

13. The article of claim 12 wherein the propulsion means is a rubber band, a mounting is attached to said forward structure having a slot to receive the rubber band and said propeller is adapted to receive the rubber hand extending from the forward structure mounting. 

